Article of footwear of nonwoven material and method of manufacturing same

ABSTRACT

A method of forming a portion of an article of footwear includes the steps of providing a last having an exterior surface, extruding a plurality of polymeric fibers, projecting a stream of the extruded polymeric fibers onto the last to form a mat having the shape of the exterior of the last, and subjecting the mat to heat and pressure in a mold.

FIELD OF THE INVENTION

This invention relates to an article of footwear formed of a nonwovenmaterial and a method of manufacturing an article of footwear formed ofa nonwoven material.

BACKGROUND OF THE INVENTION

Nonwoven fabrics, herein defined as structures made by bonding and/orinterlocking polymeric fibers by mechanical or thermal means, arecommonly used in many industries for many applications including, forexample: (i) medical products, including surgical gowns, drapes, facemasks, bouffant caps, surgical caps, footwear coverings, and slippers;(ii) protective coverings for automobiles, boats, airplanes, bicycles,lawn furniture, lawn mowers, and grills; (iii) apparel, includingindustrial work wear, pants, shirts, jackets, gloves, headwear, andsocks; (iv) personal care products such as diapers, training pants,adult incontinence products, and feminine hygiene products; and (v)filtration.

Two common methods of forming nonwoven fabrics are melt-blowing andspunbonding. The melt-blowing process typically includes extruding amolten thermoplastic material through a plurality of fine diecapillaries to form molten fibers. The fibers enter a high velocity gasstream, usually air, which attenuates the fibers so as to reduce theirdiameters. Thereafter, the high-velocity gas stream deposits the fiberson a collecting surface to form a substantially planar fabric, commonlyreferred to as a bat, mat web or sheet, which is comprised of randomlydisbursed fibers. Patents that are representative of the melt-blowingprocess include U.S. Pat. No. 3,825,379 to Lohcamp et al. as well asU.S. Pat. No. 4,714,647 to Shipp, Jr. et al.

In contrast, the spunbonding process typically includes extruding amolten thermoplastic material through a plurality of fine spinnerettecapillaries to form molten fibers. The fibers then enter a gas streamhaving less velocity than that of the melt-blowing process. The gasstream reduces the diameters of the fibers and deposits the fibers on acollecting surface, thereby forming a substantially planar fabric.Patents that are representative of the spunbonding process include U.S.Pat. No. 3,692,618 to Dorschner et al. and U.S. Pat. No. 4,340,563 toAppel et al. The difference between melt-blowing and spunbonding relatesto the continuity and diameter of the fibers. Whereas melt-blown fibershave diameters that are generally smaller than 10 microns, spunbondedfibers have diameters that are generally between 10 and 30 microns.Melt-blown fibers often include both continuous and discontinuousfibers, since their smaller diameters tends to result in breakage of thecontinuous fibers, as contrasted with spunbond fibers that includeprimarily continuous fibers.

The majority of patents relating to the manufacture of nonwoven fabricsfocus on the formation of a substantially planar material having auniform thickness. However, U.S. Pat. No. 6,146,580 to Bontaites, Jr.discloses a method of manufacturing a nonwoven materials in which fibersare deposited on a contoured drum as the drum rotates. The result is asubstantially planar material having the contour of the drum imprintedon one surface. Furthermore, the process discloses the manufacture ofsurgical masks using a form in the shape of a surgical mask. U.S. Pat.No. 5,575,874 to Griesbach, III et al. also discloses a process by whicha textured or perforated material is formed.

Melt-blown and spunbonded fabrics have been incorporated into footwearin applications including coverings, composite uppers and insoles, andcombination nonwovens. In relation to coverings, the primary use fornonwoven materials appears to be for medical products including footwearcoverings and slippers. Patents assigned to Kimberly-Clark Worldwide,Inc., including U.S. Pat. Nos. 5,952,252; 5,939,341; 5,695,377;5,688,157; and 5,652,051, are exemplary of such uses. In combinationwith other materials, nonwoven fabrics have been incorporated into shoeuppers and insoles. U.S. Pat. No. 4,603,075 to Dergarabedian disclosesan insole composite comprised of a nonwoven fabric and woven polymericscrim that are saturated with a curable or cross-linkable polymer. U.S.Pat. No. 4,663,222 to Ohue et al. discloses a nonwoven fabric that isheat-bonded to the inner side of a leather shoe to improve comfort andimpart resistance to rain and water. U.S. Pat. No. 4,426,420 to Likhyanidiscloses a spunbonded fabric containing both elastic and non-elasticfibers so as to impart greater stretch and resilience to the fabric. Asimilar process for melt-blown fibers is disclosed in U.S. Pat. No.5,238,733 to Joseph et al.

It is an object of the present invention to provide a method ofproducing an article of footwear formed of nonwoven material thatreduces or overcomes some or all of the difficulties inherent in priorknown devices. Particular objects and advantages of the invention willbe apparent to those skilled in the art, that is, those who areknowledgeable or experienced in this field of technology, in view of thefollowing disclosure of the invention and detailed description ofcertain preferred embodiments.

SUMMARY

The principles of the invention may be used to advantage to provide amethod of forming an article of footwear that includes a step ofdepositing polymeric fibers onto a surface of a last to form a nonwovenmaterial having a shape that corresponds with the surface of the last.The nonwoven material may then be incorporated into an article offootwear. Such footwear provides improved breathability and moldability,abrasion resistance, stretch and recovery, water resistance, andrecyclability.

In accordance with a first aspect, a method of forming a portion of anarticle of footwear includes the steps of providing a last having anexterior surface, extruding a plurality of polymeric fibers, projectinga stream of the extruded polymeric fibers onto the last to form a mathaving the shape of the exterior of the last, and subjecting the mat toheat and pressure in a mold.

In accordance with another aspect, a method of forming an article offootwear includes the steps of providing a last having an exteriorsurface, providing a vacuum at the exterior surface of the last,extruding a plurality of polymeric fibers, depositing at least some ofthe polymeric fibers onto the last to form a mat having the shape of theexterior of the last, subjecting the mat to heat and pressure in a moldto form an upper, and securing the upper to a sole assembly.

In accordance with yet another aspect, an upper for an article offootwear includes a mat of nonwoven extruded polymeric fibers formed ina shape of an upper for an article of footwear, with the upper beingseamless.

In accordance with a further aspect, an article of footwear includes asole assembly, and an upper secured to the sole assembly, with the uppercomprising a mat of nonwoven extruded polymeric fibers and beingseamless.

In accordance with yet a further aspect, an upper of an article offootwear is formed by the steps of providing a last having an exteriorsurface, providing a vacuum at the exterior surface of the last,extruding a plurality of polymeric fibers, projecting a stream of theextruded polymeric fibers onto the last to form a mat having the shapeof the exterior of the last, and subjecting the mat to heat and pressurein a mold to form an upper.

Substantial advantage is achieved by forming an article of footwear oran upper of an article of footwear of a nonwoven material. Inparticular, certain embodiments produce an upper that is breathable andcomfortable, with improved moldability, abrasion resistance, stretch andrecovery, and recyclability. Such footwear also has unique performanceand aesthetic characteristics and reduced waste.

These and additional features and advantages disclosed here will befurther understood from the following detailed disclosure of certainembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an article of footwear having an upperformed of nonwoven material in accordance with a certain embodiments.

FIG. 2 is a perspective view of a method of forming the upper of FIG. 1by deposting nonwoven fibers on a last.

FIG. 3 is a perspective view of a mold used in the formation of theupper of the article of footwear of FIG. 1.

The figures referred to above are not drawn necessarily to scale andshould be understood to provide a representation of the invention,illustrative of the principles involved. Some features of the article offootwear or upper of nonwoven material and their method of manufacturedepicted in the drawings have been enlarged or distorted relative toothers to facilitate explanation and understanding. The same referencenumbers are used in the drawings for similar or identical components andfeatures shown in various alternative embodiments. Uppers or articles offootwear of nonwoven material and the methods of manufacture asdisclosed herein would have configurations and components determined, inpart, by the intended application and environment in which they areused.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS

Referring to the drawings, wherein like numerals indicate like elements,an upper for an article of footwear a method of forming an article offootwear and in accordance with various embodiments are illustrated. Theaccompanying figures illustrate only the formation of an article offootwear intended for use on a left foot of a wearer. It is to beappreciated that the various embodiments also include a right article offootwear, such footwear being the mirror image of the left foot articledepicted herein.

An article of footwear 10 in accordance certain embodiments is depictedin FIG. 1 and includes an upper 12. Attached to the lower portion ofupper 12 is a conventional sole assembly 14. As seen here, sole assembly14 includes a midsole 16 to which upper 12 is secured by adhesive,stitching or any other suitable fastening means. An outsole 18 issecured to midsole 16 by adhesive or other suitable fastening means. Itis to be appreciated that is certain embodiments, sole assembly 14 mayinstead be a unitary structure and not formed of two separate midsoleand outsole elements.

The construction of upper 12 is illustrated in FIGS. 2-3. As seen inFIG. 2, a last 20 is formed of a frame 22, which comprises a pluralityof frame members 24 arranged such that they roughly define the shape ofan upper for an article of footwear. Frame 22 may be formed of metal,e.g., aluminum. However, it is to be appreciated that other materials,such as plastics, or composite materials may be used to form frame 22.Other materials suitable for use as frame 22 will become readilyapparent to those skilled in the art, given the benefit of thisdisclosure. A mesh material 26 is disposed on the exterior of frame 22.In the illustrated embodiment, mesh material 26 is formed of metal,e.g., aluminum. Other suitable materials include fabrics woven withpolyester or nylon filaments, perforated films, perforated plastic. Itis to be appreciated that other materials, such as plastics or compositematerials may be used to form mesh material 26. Other materials suitablefor use as mesh material 26 will become readily apparent to thoseskilled in the art, given the benefit of this disclosure.

A mounting member 28 having an aperture 30 extending therethrough issecured to frame 22 at an upper edge of last 20 where the ankle openingof the upper to be formed is located. Aperture 30 is in fluidcommunication with the interior of frame 22. Mounting member 28 may beformed of an elastomeric material, metal, plastic or any other suitablematerial.

A vacuum source such as a pump 32 is connected by way of a conduit 34 toaperture 30 in mounting member 28. Pump 32 is used to apply a vacuum atan exterior surface 36 of last 20.

In various embodiments, a robot 38 is used to hold last 20 in a desiredposition. Robot 38 may be a multi-axis robot as shown here, therebyallowing last 20 to be manipulated in virtually any direction. Robot 38has a gripper element 40 that securely holds last 20 in a desiredposition. As illustrated here, gripper element 40 is seen secured aboutmounting member 28.

A stream 42 of melt-blown or spunbonded fibers is projected onto last20. The fibers collect on the surface of last 20 and form a continuousnonwoven covering. When a sufficient quantity of fibers collect on thesurface of last 20, thereby forming upper 12, last 20 is removed fromfiber stream 42 and permitted to cool. Last 20 may be removed from fiberstream 42 in many ways including physically moving last 20 away fromfiber stream 42, redirecting fiber stream 42 so that it no longerimpacts last 20, or by stopping the flow of fiber stream 42. Then, soleassembly 14 is attached to upper 12 using conventional techniques. Last20 is removed from the interior of upper 12, thereby defining a recessfor receiving the foot of a wearer. In certain embodiments, upper 12 isremoved from last 20 prior to attachment of sole assembly 14. Upper 12may be subject to further treatment prior to or after attachment of soleassembly 14 to upper 12.

In the illustrated embodiment, stream 42 is projected from a head ornozzle 44. Nozzle 44 is connected by a conduit 46 to a reservoir 48 ofmaterial 50. In certain embodiments, material 50 is a moltenthermoplastic material, and nozzle 44 extrudes material 50 into a streamof melt-blown or spunbond material. It is to be appreciated that nozzle44 can have any desired shape, and that its shape may vary based adesired characteristic of the fibers in stream 42 and based on thematerial 50 from which the fibers are extruded.

In the illustrated embodiment, a robot 52 is used to hold nozzle 44.Robot 52 may be a multi-axis robot as shown here, thereby allowingnozzle 44 to be manipulated in virtually any direction. Robot 52 has agripper element 54 that securely holds nozzle 44 in a desired position.As illustrated here, gripper element 54 is seen secured about nozzle 44.

It is to be appreciated that in various embodiments, last 20 can be heldin a fixed position and robot 52 can be used alone to manipulate stream42 about last 20, thereby covering last 20 with the desired amount ofmaterial. In such an embodiment, robot 38 is not required. In otherembodiments, nozzle 44 can be held in a fixed position and robot 38 canbe used alone to manipulate the position of last 20 with respect tostream 42, thereby ensuring that the desired amount of material isdeposited on last 20 in the appropriate areas. In such an embodiment,robot 52 is not required.

It is to be appreciated that upper 12 can be formed with varyingthickness across its surface, thereby allowing upper 12 to be customizedfor a desired function. Thus, one or more portions of upper 12 can beformed of a thicker or thinner layer of material than that found inother portions, thereby altering characteristics, such as strength andflexibility of the material, throughout upper 12.

Material 50 that is used to form upper 12 can be any desired polymericmaterial capable of being spunbond or meltblown to produce a nonwovenfiber. Suitable examples of material 50 include, for example,thermoplastic urethane (TPU), polyurethane, or a high flex moduluspolyether block amide, such as PEBAX®, which is manufactured by theAtofina Company. Other suitable materials used to produce nonwovenfibers used for forming articles of footwear will become readilyapparent to those skilled in the art, given the benefit of thisdisclosure.

Once a desired quantity of fibers is deposited on last 20, upper 12 isthen placed in a mold assembly 56, as seen in FIG. 3. In the illustratedembodiment, mold assembly 56 is formed of a first portion 58 and asecond portion 60. A first recess 62 is formed in first portion 58 and amating second recess 64 is formed in second portion 60. As illustratedhere, first portion 58 has a plurality of pins 66 that are received incorresponding apertures 68 formed in second portion 60 in order toregister and align first portion 58 with second portion 60. Moldassembly 56 is closed about upper 12 and subject to heat and pressure,which imparts additional strength to upper 12. Upper 12 is then removedfrom mold assembly 56 and last 20 is removed from upper 12. Soleassembly 14 can then be secured to upper 12 by stitching, adhesive orany other suitable fastening means.

Mold assembly 56 may be modified to impart surface irregularities inupper 12 during the molding process. As seen here, a plurality ofrecesses 70 are formed within recess 64 of second portion 60. Theserecesses 70 form projections 72 on upper 12 as seen in FIG. 1. In otherembodiments, one or more projections can be formed in first recess 62 orsecond recess 64, which will form corresponding recesses in upper 12. Itis to be appreciated that any number and configuration of surfaceirregularities can be formed on upper 12 by modifying the surface offirst recess 62 of first portion 58 or second recess 64 of secondportion 60. Thus, both the structure and aesthetic appeal of upper 12can be varied by varying the configuration of mold assembly 56.

The surface of upper 12 can be sealed to make it more “film-like” duringthe molding process to provide a water resistant upper 12, therebyimproving the functionality of upper 12. Upper 12, being formed of anon-woven material, advantageously exhibits improved breathability andmoldability, as well as abrasion resistance, and improved stretch andrecovery.

In certain embodiments, in which TPU is used to form upper 12, a soleassembly 14 comprising a midsole 16 and or an outsole 18, can bedirectly bonded to upper 12 without the need for primers or adhesive,thereby reducing the materials needed for assembly of footwear 10, andfacilitating recycling of footwear 10.

In light of the foregoing disclosure of the invention and description ofvarious embodiments, those skilled in this area of technology willreadily understand that various modifications and adaptations can bemade without departing from the scope and spirit of the invention. Allsuch modifications and adaptations are intended to be covered by thefollowing claims.

1. A method of forming a portion of an article of footwear comprisingthe steps of: providing a last having an exterior surface; extruding aplurality of polymeric fibers; projecting a stream of the extrudedpolymeric fibers onto the last to form a mat having the shape of theexterior surface of the last; and subjecting the mat to heat andpressure in a mold.
 2. The method of claim 1, wherein the polymericfibers are formed of polyurethane.
 3. The method of claim 1, wherein thepolymeric fibers are formed of a polyether block amide.
 4. The method ofclaim 1, wherein the last comprises a frame covered by a mesh material.5. The method of claim 4, wherein the frame and mesh material are formedof metal.
 6. The method of claim 1, wherein the polymeric fibers aremeltblown.
 7. The method of claim 1, wherein the polymeric fibers arespunbond.
 8. The method of claim 1, wherein the step of subjecting themat to heat and pressure in the mold is performed with the mat on thelast.
 9. The method of claim 8, further comprising the step of removingthe mat from the last.
 10. The method of claim 1, wherein the moldincludes at least one surface irregularity to form a mating surfaceirregularity on the mat.
 11. The method of claim 1, wherein the moldincludes a recess to form a mating projection on the mat.
 12. The methodof claim 1, wherein the mold includes a projection to form a matingrecess on the mat.
 13. The method of claim 1, further comprising thestep of moving the last as the polymeric fibers are projected onto thelast.
 14. The method of claim 13, wherein the step of moving the last isperformed with a robot.
 15. The method of claim 1, further comprisingthe step of moving the stream of extruded polymeric fibers with respectto the last as the polymeric fibers are projected onto the last.
 16. Themethod of claim 15, wherein the step of moving the stream of extrudedpolymeric fibers is performed with a robot.
 17. The method of claim 1,further comprising the steps of moving the last and moving the stream ofextruded polymeric fibers with respect to the last as the polymericfibers are projected onto the last.
 18. The method of claim 1, whereinthe mat forms an upper for an article of footwear.
 19. The method ofclaim 1, further comprising the step of providing a vacuum at theexterior surface of the last.
 20. The method of claim 1, wherein the matis water resistant.
 21. A method of forming an article of footwearcomprising the steps of: providing a last having an exterior surface;providing a vacuum at the exterior surface of the last; extruding aplurality of polymeric fibers; depositing at least some of the polymericfibers onto the last to form a mat having the shape of the exterior ofthe last; subjecting the mat to heat and pressure in a mold to form anupper; and securing the upper to a sole assembly.
 22. The method ofclaim 21, wherein the polymeric fibers are formed of polyurethane. 23.The method of claim 21, wherein the polymeric fibers are formed ofpolyether block amide.
 24. The method of claim 21, wherein the lastcomprises a frame covered by a mesh material.
 25. The method of claim21, wherein the polymeric fibers are meltblown.
 26. The method of claim21, wherein the polymeric fibers are spunbond.
 27. The method of claim21, further comprising the step of removing the upper from the last. 28.The method of claim 21, wherein the mold includes at least one surfaceirregularity to form a mating surface irregularity on the upper.
 28. Themethod of claim 21, wherein the mold includes a recess to form a matingprojection on the upper.
 30. The method of claim 21, wherein the moldincludes a projection to form a mating recess on the upper.
 31. Themethod of claim 21, wherein the sole assembly includes a midsole and anoutsole.
 32. The method of claim 20, further comprising the step ofmoving the last as the polymeric fibers are deposited on the last. 33.The method of claim 21, further comprising the step of moving the streamof extruded polymeric fibers with respect to the last.
 34. The method ofclaim 21, further comprising the steps of moving the last as thepolymeric fibers are deposited on the last and moving the stream ofextruded polymeric fibers with respect to the last.
 35. the method ofclaim 21, wherein the upper is water resistant.
 36. An upper for anarticle of footwear comprising, in combination: a mat of nonwovenextruded polymeric fibers formed in a shape of an upper for an articleof footwear, the upper being seamless.
 37. The upper of claim 36,wherein the polymeric fibers are formed of polyurethane.
 38. The upperof claim 36, wherein the polymeric fibers are formed of a polyetherblock amide.
 39. The upper of claim 36, wherein the polymeric fibers aremeltblown.
 40. The upper of claim 36, wherein the polymeric fibers arespunbond.
 41. The upper of claim 36, further comprising a surfaceirregularity on an exterior surface of the upper.
 42. An article offootwear comprising, in combination: a sole assembly; and an uppersecured to the sole assembly, the upper comprising a mat of nonwovenextruded polymeric fibers and being seamless.
 43. The article offootwear of claim 42, wherein the sole assembly includes a midsole andan outsole.
 44. The article of footwear of claim 42, wherein thepolymeric fibers are formed of polyurethane.
 45. The article of footwearof claim 42, wherein the polymeric fibers are formed of polyether blockamide.
 46. The article of footwear of claim 42, wherein the polymericfibers are meltblown.
 47. The article of footwear of claim 42, whereinthe polymeric fibers are spunbond.
 48. The article of footwear of claim42, further comprising a surface irregularity on an exterior surface ofthe upper.
 49. An upper of an article of footwear formed by the stepsof: providing a last having an exterior surface; providing a vacuum atthe exterior surface of the last; extruding a plurality of polymericfibers; projecting a stream of the extruded polymeric fibers onto thelast to form a mat having the shape of the exterior of the last; andsubjecting the mat to heat and pressure in a mold to form an upper. 50.The method of claim 49, wherein the polymeric fibers are formed ofpolyurethane.
 51. The method of claim 49, wherein the polymeric fibersare formed of a polyether block amide.
 52. The method of claim 49,wherein the last comprises a frame covered by a mesh material.
 53. Themethod of claim 52, wherein the frame and mesh material are formed ofmetal.
 54. The method of claim 49, wherein the polymeric fibers aremeltblown.
 55. The method of claim 49, wherein the polymeric fibers arespunbond.
 56. The method of claim 49, wherein the step of subjecting themat to heat and pressure in the mold is performed with the mat on thelast.
 57. The method of claim 56, further comprising the step ofremoving the mat from the last.
 58. The method of claim 49, wherein themold includes at least one surface irregularity to form a mating surfaceirregularity on the mat.
 59. The method of claim 49, wherein the moldincludes a recess to form a mating projection on the mat.
 60. The methodof claim 49, wherein the mold includes a projection to form a matingrecess on the mat.
 61. The method of claim 49, further comprising thestep of moving the last as the polymeric fibers are projected onto thelast.
 62. The method of claim 61, wherein the step of moving the last isperformed with a robot.
 63. The method of claim 49, further comprisingthe step of moving the stream of extruded polymeric fibers with respectto the last as the polymeric fibers are projected onto the last.
 64. Themethod of claim 63, wherein the step of moving the stream of extrudedpolymeric fibers is performed with a robot.
 65. The method of claim 49,further comprising the steps of moving the last and moving the stream ofextruded polymeric fibers with respect to the last as the polymericfibers are projected onto the last.